An RFID tag 1 for a rubber product is provided with a coupling transformer 40, an RF chip 10 connected to a secondary side of the coupling transformer, a printed circuit board 20 on which the RF chip is mounted, and an antenna 30, wherein the antenna comprises a coil section 31, a first element 32 extending from one end of the coil section, and a second element 33 extending from another end of the coil section in parallel with the first element and shorter than the first element, the coil section has fewer windings than the coupling transformer 40 on the secondary side, and the printed circuit board 20 is held in a gap between strands of the coil section such that the coil section forms a primary side of the coupling transformer.
Legal claims defining the scope of protection, as filed with the USPTO.
1. An RFID tag for a rubber product, the RFID tag comprising: a coupling transformer, an RF chip connected to a secondary side of the coupling transformer, a printed circuit board on which the RF chip is mounted, and an antenna, wherein the antenna comprises a coil section, a first element extending from one end of the coil section, and a second element extending from another end of the coil section in parallel with the first element and shorter than the first element, the coil section has fewer windings than a coil section on the secondary side of the coupling transformer, and the printed circuit board is held in a gap between strands of the coil section such that the coil section forms a primary side of the coupling transformer.
2. The RFID tag for a rubber product according to claim 1, wherein the RFID tag is for a rubber product containing carbon black.
3. The RFID tag for a rubber product according to claim 1, comprising: insulating layers on both upper and lower surfaces of the printed circuit board.
4. The RFID tag for a rubber product according to claim 1, wherein the coil section, the first element, and the second element are formed from a single conducting wire.
5. The RFID tag for a rubber product according to claim 1, wherein an axis of a secondary coil of the coupling transformer is aligned with an axis of the coil section.
6. The RFID tag for a rubber product according to claim 5, wherein a diameter of the coil section of the antenna is the same as an outer diameter of the coil section of the coupling transformer.
7. The RFID tag for a rubber product according to claim 5, wherein a diameter of the coil section of the antenna is greater than an outer diameter of the coil section of the coupling transformer.
8. The RFID tag for a rubber product according to claim 5, wherein provided that λ is the wavelength of a radio wave at a communication frequency, a portion consisting of the first element, the second element, and the coil section has an electrical length of λ/4, a diameter of the coil section of the antenna is the same as or greater than an outer diameter of the coil section of the coupling transformer, and an impedance of the RF chip is 100 times or greater than an impedance measured between the first element and the second element of the antenna.
9. The RFID tag for a rubber product according to claim 5, wherein provided that λ is the wavelength of a radio wave at a communication frequency, a portion consisting of the first element, the second element, and the coil section has an electrical length of λ/4, a diameter of the coil section of the antenna is the same as or greater than an outer diameter of the coil section of the coupling transformer, and an impedance of the RF chip is 10 kΩ or less.
10. The RFID tag for a rubber product according to claim 1, wherein provided that λ is the wavelength of a radio wave at a communication frequency, a portion consisting of the first element, the second element, and the coil section has an electrical length of λ/4.
11. The RFID tag for a rubber product according to claim 1, wherein provided that λ is the wavelength of a radio wave at a communication frequency, a portion consisting of the first element, the second element, and the coil section has an electrical length of λ/2.
12. The RFID tag for a rubber product according to claim 1, wherein provided that λ is the wavelength of a radio wave at a communication frequency, a portion consisting of the first element, the second element, and the coil section has an electrical length of (3/4)λ.
13. The RFID tag for a rubber product according to claim 1, wherein provided that λ is the wavelength of a radio wave at a communication frequency, a portion consisting of the first element, the second element, and the coil section has an electrical length of (5/8)λ.
14. The RFID tag for a rubber product according to claim 1, wherein an impedance of the RF chip is 100 times or greater than an impedance measured between the first element and the second element of the antenna.
15. The RFID tag for a rubber product according to claim 1, wherein an impedance of the RF chip is ranged from a few kΩ to 10 kΩ.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
February 12, 2021
April 1, 2025
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